Robust Control System for the Optical Extra-precise Vibration Isolation System

The robust control theory is used to solve the uncertainty of the optical extra-precise vibration isolation system. The wavelet theory is used to analyze the random vibration signal in the time-frequency domain and get the low frequency signal from the random vibration signal. The robust controller designed by the robust control theory is used to restrain the low frequency vibration. The active vibration isolation exploits the theory of robust control, which overcomes the uncertainty of model and the disturbance, and makes the control system to restrain the uncertainty of the model and the disturbance of the vibration. The simulation results prove that this method has shown good robustness and control precision in the vibration isolation of the optical extra-precise instrument and have good performance on restraining the low frequency vibration.     

Prediction model on the radiated electromagnetic interference of wiper motor in automobile

According to the theory of signals and systems, the radiated system’s transfer function is derived, the radiation electromagnetic interference(EMI) simulation model of the wiper motor based on the finite integration technique(FIT) algorithm is established, and the whole system’s transfer function are obtained in the environment of simulation software CST. The terminal voltage of the motor,as the noise source of radiation system, can be gained with experiment. The radiation electric field can be calculated by transfer function multiplying motor’s terminal voltage. Then the complex question of motor’s system level radiation can be transformed to the simple problems of computing system’s transfer function and the motor’s terminal voltage. By comparing simulation and experiment results, it is showed that the radiated EMI simulation model of the motor can demonstrate the essential feature of motor’s electromagnetic radiation system accurately, which means that it can be used in the research of wiper motor EMC forecasting.     

Application of multi-dimension parallel genetic algorithm to energy-saving optimum control of trains in following operation

In order to study the energy-saving optimum control strategy of a leading train and a tracing train in following operation under a moving block system,an energy-saving control model of trains is created. The aims of the model are energy consumption and trip time error. The control variables of this model are the operating handle level and the train’s position when the operating handle level is changed. Based on the model,the static and dynamic speed restraints are put forward. The static speed restraints are defined by the line conditions and the dynamic speed restraints of the tracing train caused by the leading train for the sake of safety. This problem is solved with the help of multi-dimension parallel genetic algorithm (GA) and external punishment function. During the solving process,the crossover probability and the mutation probability are adjusted dynamically according to the GA generation to improve the efficiency of the coarse grain search and the fine grain search. Ramps divided into three parts and the real number coding are adopted to shorten the length of chromosomes and improve the speed of convergence. Its correctness and effectiveness are validated at a simulation platform of train operation.     

An improved rotor side control strategy of double fedwind turbine generation system

Based on a on site wind turbine’s output active power vs. generator speed curve, the shortage of conventional power control strategies of doubly fed wind turbine generation system are analyzed. Considering the generator speed restriction and active power fast track control requirement, the power decoupling control strategy in the rotor side converter and variable pitch control strategy are improved, that is, an output mechanical torque of wind turbine and the generator speed of DFIG are used in the rotor side active power control loop in order to achieve an accurate optimal speed control, as well as a direct active power control method is also adopted in the variable pitch control strategy. Finally, the overall operational performances of DFIG wind turbine generation system using the proposed control strategies are simulated, and also compared with the conventional control strategies. The results show that the improved control strategy is more valid and correct.     

An improved FCM algorithm and its application to EEG signal processing

Most of the popular EEG classifiers need to be supervised and their parameters have to be trained by a number of train data in advance.That’s the reason why they cannot be used in the real-time circumstances.In this paper,a new FCM unsupervised classification algorithm is proposed which is based on the density size of data dot and mahalanobis distance.Then,the algorithm is used to classify the EEG signals from the database of the second session of 2003 BCI competition.The EMD algorithm is used to decompose the EEG and extract the characteristic values,and then these values are classified by the proposed FCM algorithm.The experimental results show the algorithm’s feasibility and validity in the EEG classification field.     

Vibration control of active constrained layer damping structure

A finite element dynamic model for plates with active constrained layer damping (ACLD) treatments is derived based on the constitutive equations of elastic, viscoelastic and piezoelectric materials by application of Hamilton principle. The closed loop control system considering displacement and velocity feedback of self sensing voltage from sensor layer is developed. The dynamic behaviors of active constrained layer damping (ACLD) plates including nature frequencies, loss factors and responses in frequency domain are investigated. The influence of control gains on vibration suppression is discussed. Numerical examples demonstrate the validity of the finite element model and the control strategy approach. The proposed control strategy can be widely used to structure vibration control with ACLD patches due to its simple scheme and easy implementation.     

A Control Algorithm to Regulate the Active and Reactive Power and Simulation Research of Dual-frequency Dual-Buck Inverter

This paper deduceS the control algorithm ,which can both regulate the active and reactive power of the novel dual-frequency dual-Buck inverter, and the control function. The control function based on one cycle control can control the AC-side active and reactive power by simple circuit. The simulation is given and the results prove the validity of the theory analysis. This inverter is valuable for the research of grid-connected inverters.     

Design of PID control algorithm on large diameter tiled-grating

To realize the long-time dynamic stability for the tiled-grating control system,a PID algorithm based on the analysis of the four-dimensional degree of freedom mathematical model for the tiled-grating is developed. Two improvements are made in incremental PID algorithm. The latches compensation method is used to avoid saturated loss,and the four-point center difference method is applied to avoid interference. The splicing spot photos of the tiled-grating’s closed-loop control experiments demonstrate that the tiled-grating which employs the improved PID algorithm can acquire a long-time stability as well as the stability can keep one hour.     

The compensation method for the random time-delay of the feedbackchannel and the forward channel in the networked control system

An improved predictive control method is presented to compensate the random time delay in the networked control system. The feedback time delay is compensated by predictive controller based on softened increment input strategy. The forward time delay is unknown for controller, so an extra feedback loop is added to compensate the delay by estimating the error between the actual control signal effected on plant and the output of controller in historical moment. For the controlled system with unknown or slowly varying parameters, the networked feedback correction algorithm is discussed based on a modified recursive least-squares identi cation algorithm. The system stability is analyzed and the simulation results show that the time delay in the networked control system can be accurately compensated. The excellent network performance is ensured with this strategy.     

Application and research of improved artificial immune network to power short-term load forecasting

According to the deficiencies of load forecasting model at present,a short-term load forecasting model based on optimized clone immune and BP neural network (BPNN) is presented. In the design of artificial immune network (AIN),the principle of immune network regulation is used in a creative way and the method of immune programming is used to evolve the network structure. The probability of selective antibody concentration,a new fitness function of neurons,a new mutation operator and a new self-adaptive chaos mutation operator are adopted in the AIN. The excitation function controls the BP algorithm which greatly accelerates convergence of BP training,the self adaptable strategy based on clone immune optimizes the controlled BP algorithm,and it improves its global searching ability better than the BP algorithm optimized by chaos and avoids the algorithm to be trapped in local minimum and improves the prediction accuracy.     

Ratio control strategy for solving system response lag of continuously variable transmission system

Generally, there’s a system response lag in the continuously variable transmission system, and this leads to a deviation of the engine work point from the optimal operation line of the minimum fuel consumption. To reduce the influence of system response lag, a new CVT ratio control strategy with the system response lag parameter during computing target ratio is proposed. Simulation results indicate that the proposed control strategy can overcome the effect of system response lag, so as to keep the engine work point on the optimal operation line effectively. A comparison of fuel consumption is made between the proposed control strategy and the traditional one by simulation, and results indicate that the proposed control strategy reduces the fuel consumption of the system by 2.85％.     

The design of torque dynamic sliding mode controller in permanent magnet synchronous generator for wind turbine

Permanent magnet synchronous generator for wind turbine is a multivariable nonlinear system with strong coupling. Considering the influence of the volatile parameters of the generator on the performance of vector control, the torque dynamic sliding-mode control strategy is further studied. The proposed first order dynamic sliding-mode control strategy reduces the chattering by using a new switch function constituted with derivative element. With the dynamic sliding-mode controller in the power outer loop, the PMSG vector control system shows excellent robustness and insensitivity to the parameters and disturbance, which is confirmed by simulation.     

Electronically-controlled Hydraulic Throttle Actuator with High Speed On-off Valve

This paper develops the control system of electronically controlled throttle with high speed on off valve.The electronically controlled hydraulic actuator is used to control the throttle controlled by high speed on off valve.The mathematical model of the control system is established.Because of the existing turn on time of high speed on off valve,the problem which throttle position is controlled actuately is solved by adding a nonlinear compensating block.Main parameters affecting throttle position control are discussed.Simulation research and road test prove that the control system is applicable and feasible.     

INTRODUCTION TO A NEW AUTOPROGRAMMING SYSTEM FOR NC LATHE

This paper deals with the BCH autoprogramming system based on the principle of "representing shap with numbers", With this system, the organization of turning process can be accomplished by inputting only some codes and a few characteristic parameters, and the NC block instructions to control the NC lathe via control unit can be output in turn so that it is possible to write a part program at the shop floor which is benifitian for developing a new programming method to be used in a multistage computer manage system with communicating interface.     

The predictive control of an incremental model based on tracking error

An algorithm of incremental model predictive control is proposed to solve a class of industrial production process real-time tracking problems. The basic idea is to establish a predictive model by adopting speed response on the basis of tracking error, and realize the optimization of the second time performance by using the soft constraint of the increment of control quantity and the online rolling optimization method. The theoretical analysis and Matlab simulation results show that the control algorithm can obtain good tracking performance, smooth dynamic response of the controlled object and strong robustness of the closed-loop system.     

Control strategy and parameters optimization outsourcing production inventory system under uncertainty

This paper proposes a control strategy for the optimal control of the outsourcing production inventory system based on production point and production batch. The statistical probability distribution is used to describe the uncertainty of the production capacity of cooperative enterprises and the transportation time. The optimization model of the control parameters is developed with random production capacity for cooperative enterprises and random transportation time in order to minimize the holding cost,setup cost as well as the cost of production capacity waste. A simulation-based control parameters optimization algorithm is designed to solve the proposed model. The control strategy of production inventory system and the control parameters optimization algorithm proposed are validated by an example. We analyze the influence of the variation of the production point and production batch to the performance of the outsourcing production inventory system.     

ON THE PROBLEM OF SWITCHING CONDITIONS FOR A KIND OF MINIMUM-TIME CONTROL SYSTEMS

The paper provides a detailed study of switching conditions of minimum-time control systems based on application in engineering. By analysis in theory and experiment, the authors deduce a set of switching conditions with state and control variabes inequality constraints, the variations of system parameters and the time-delay of computer in real time control. As an example, a DC motor speed control system is considered. By digital simulation and physical experiments,these conditions proved to be correct. The method in this paper is also suitable for other control systems using compound control algorithm.     

The main loop and servo loop structure control strategy of ESC

Aiming at the control of electronic stability control system(ESC)which can enhance the handling stability in limited condition,the hierarchical control structure control strategy of ESC including main loop and servo loop is proposed. The first order sliding mode control is used in the main loop and the sliding mode plane and control law are designed. The output of main loop is the accessional yaw moment. The nine points with five states control which can approximately simulate human thinking is used in the servo loop. The brake pressure is controlled by the servo loop aiming at the desired slip rate and the accessional yaw moment is generated by brake force. The driver in the loop simulation bench is designed and the online test of the control strategy is carried on. The test results indicate that the handling stability and active safety are enhanced remarkably by the ESC control strategy in the drive condition of low adhesion road and driver handling vehicles immoderately,and the testing facticity and the pertinency of developed control strategy are improved by the driver in the loop simulation.     

The application to simplify the complicated power grid through adjacent two-node equivalent method

Most real power systems are not radial networks and evaluation of the stability often needs to establish electromagnetic transient simulation models. So the network equivalent is required first and foremost. The adjacent two-node equivalent method, which considers the coupling impedance between equivalent nodes, is used to realize the simplification and modeling to complex power grid. The analysis and simulation on both the HVDC system from Deyang to Baoji and a real extra-high voltage AC transmission system in South China shows that the static performance of the simulated system by using the adjacent two-node equivalent method is completely equivalent to the original one, as well as the performance of dynamic equivalent is in a satisfied level. Thus the transient system model simplified can be well established to support research of power grid’s security and stability.     

Experimental Setup of Rotating Air bearing Table System for Active Vibration Control of Flexible Structure

In accordance with the present situation that there is a lack of deeper investigation of active vibration control of rigid flexible coupled structures with rotating rigid base,the significance of the buildup of experiment system is emphasized,and every component and its function of the experiment system is introduced in detail.The experimental setup has been finished so as to make rigid base rotate within some range at some different angular speed in the state of air bearing.